add(internal): http client import

internal/config/http_client.go

@@ -0,0 +1,28 @@
+package config
+
+import (
+	"github.com/namsral/flag"
+)
+
+type (
+	HTTPClient struct {
+		BaseURL string
+		Timeout int
+	}
+)
+
+var httpClient *HTTPClient
+
+func (c *HTTPClient) Validate() error {
+	return nil
+}
+
+func (*HTTPClient) Init(prefix ...string) *HTTPClient {
+	if httpClient != nil {
+		return httpClient
+	}
+	httpClient = new(HTTPClient)
+	flag.StringVar(&httpClient.BaseURL, "http-client-base-url", "", "HTTP Client Base URL")
+	flag.IntVar(&httpClient.Timeout, "http-client-timeout", 5, "HTTP Client request timeout (seconds)")
+	return httpClient
+}

internal/http/client.go

@@ -0,0 +1,166 @@
+package http
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"strings"
+	"time"
+
+	"github.com/pkg/errors"
+
+	"github.com/crusttech/crust/internal/config"
+)
+
+type (
+	Client struct {
+		Transport *http.Transport
+		Client    *http.Client
+
+		debugLevel DebugLevel
+		config     *config.HTTPClient
+	}
+
+	Request http.Request
+
+	DebugLevel string
+)
+
+const (
+	INFO DebugLevel = "info"
+	FULL            = "full"
+)
+
+func New(flags *config.HTTPClient) (*Client, error) {
+	if err := flags.Validate(); err != nil {
+		return nil, errors.Wrap(err, "creating http client failed")
+	}
+
+	timeout := time.Duration(flags.Timeout) * time.Second
+
+	transport := &http.Transport{
+		Dial: (&net.Dialer{
+			Timeout: timeout,
+		}).Dial,
+		TLSHandshakeTimeout: timeout,
+	}
+
+	client := &http.Client{
+		Timeout:   timeout,
+		Transport: transport,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+
+	return &Client{
+		Transport: transport,
+		Client:    client,
+		config:    flags,
+	}, nil
+}
+
+func (c *Client) Debug(level DebugLevel) *Client {
+	c.debugLevel = level
+	return c
+}
+
+func (c *Client) Get(url string) (*http.Request, error) {
+	return c.Request("GET", url, nil)
+}
+
+func (c *Client) Post(url string, body interface{}) (*http.Request, error) {
+	return c.Request("POST", url, body)
+}
+
+func (c *Client) Patch(url string, body interface{}) (*http.Request, error) {
+	return c.Request("PATCH", url, body)
+}
+
+func (c *Client) Delete(url string) (*http.Request, error) {
+	return c.Request("DELETE", url, nil)
+}
+
+func (c *Client) Request(method, url string, body interface{}) (*http.Request, error) {
+	if c.config.BaseURL != "" {
+		url = strings.TrimRight(c.config.BaseURL, "/") + "/" + strings.TrimLeft(url, "/")
+	}
+
+	if c.debugLevel == "info" {
+		fmt.Println("HTTP >>>", method, url)
+	}
+
+	request := func() (*http.Request, error) {
+		if body != nil {
+			b, err := json.Marshal(body)
+			if err != nil {
+				return nil, err
+			}
+			return http.NewRequest(method, url, bytes.NewBuffer(b))
+		}
+		return http.NewRequest(method, url, nil)
+	}
+
+	req, err := request()
+	if err != nil {
+		return nil, errors.Wrap(err, "creating request failed")
+	}
+	req.Header.Add("Content-Type", "application/json")
+	return req, nil
+}
+
+func (c *Client) Do(req *http.Request) (*http.Response, error) {
+	if c.debugLevel == FULL {
+		fmt.Println("HTTP >>> (request)")
+		b, err := httputil.DumpRequestOut(req, true)
+		if err != nil {
+			fmt.Println("HTTP >>> Error:", err)
+		} else {
+			if b != nil {
+				fmt.Println(strings.TrimSpace(string(b)))
+			}
+		}
+		fmt.Println("---")
+	}
+
+	resp, err := c.Client.Do(req)
+	if c.debugLevel == FULL {
+		fmt.Println("HTTP <<< (response)")
+		if err != nil {
+			fmt.Println("HTTP <<< Error:", err)
+		} else {
+
+			b, err := httputil.DumpResponse(resp, true)
+			if err != nil {
+				fmt.Println("HTTP <<< Error:", err)
+			} else {
+				if b != nil {
+					fmt.Println(string(b))
+				}
+			}
+		}
+		fmt.Println("-----------------")
+	}
+	if err != nil {
+		if c.debugLevel == INFO {
+			fmt.Println("HTTP <<< Response error", err)
+		}
+		return nil, errors.Wrap(err, "request failed")
+	}
+	if c.debugLevel == INFO {
+		fmt.Println("HTTP <<< Response", resp.StatusCode)
+	}
+	return resp, nil
+}
+
+func ToError(resp *http.Response) error {
+	body, err := ioutil.ReadAll(resp.Body)
+	if body == nil || err != nil {
+		return errors.Errorf("unexpected response (%d, %s)", resp.StatusCode, err)
+	}
+	return errors.New(string(body))
+}

internal/http/client_test.go

@@ -0,0 +1,36 @@
+// +build external
+
+package http
+
+import (
+	"testing"
+
+	"github.com/crusttech/crust/internal/config"
+	"github.com/crusttech/crust/internal/test"
+)
+
+func TestHTTPClient(t *testing.T) {
+	client, err := New(&config.HTTPClient{
+		Timeout: 10,
+	})
+	test.Assert(t, err == nil, "%+v", err)
+	client.Debug(FULL)
+
+	req, err := client.Get("https://api.scene-si.org/fortune.php")
+	test.Assert(t, err == nil, "%+v", err)
+
+	resp, err := client.Do(req)
+	test.Assert(t, err == nil, "%+v", err)
+
+	err = func() error {
+		defer resp.Body.Close()
+		switch resp.StatusCode {
+		case 200:
+			return nil
+		default:
+			return ToError(resp)
+		}
+	}()
+
+	test.Assert(t, err == nil, "Invalid response: %+v", err)
+}